Denmark has registered 256 cases of infections with B117, a more contagious coronavirus variant first identified in Britain, health authorities told Reuters.

Denmark extended a lockdown for three weeks on Wednesday in a bid to curtail the spread of the new variant, which authorities expect to be the dominant one by mid-February.

The Nordic country has become a front-runner in monitoring coronavirus mutations by running most positive tests through genome sequencing analysis.

Between mid-November and Jan 10, 256 Danes were infected with the new variant, the State Serum Institute said in its report.